The following table shows the currently accepted half-life values for four parent isotopes. Earth is approximately 4.5 billion years old. Given this information and the data in the table, which of the following isotopes could today contain less than 50 percent of its parent isotope?

Rubidium-87
Thorium-232
Uranium-235
Uranium-238

emerald ash borer

the emerald ash borer is a green buprestid or jewel beetle native to north-eastern asia that feeds on ash species. females lay eggs in bark crevices on ash trees, and larvae feed underneath the bark of ash trees to emerge as adults in one to two years. hope this !

its temperature is increasing. this causes molecular vibrations to increase.